Warp knitting machine

ABSTRACT

IN A WRAP KNITTING MACHINE IN WHICH A PREFORMED WEFT IS FED TO A KNITTING ZONE IN WHICH WARP YARNS ARE KNIT THEREINTO, THE IMPROVEMENT COMPRISING MEANS FOR FEEDING AT LEAST TWO PREFORMED WEFTS SIDE BY SIDE THROUGH THE KNITTING ZONE AND THEREBY FORMING A CORRESPONDING TWO LONGITUDINAL STRIPS OF FABRIC.

Nov. 9, 1971 E. EHRLICH ETAL WARP KNITTING MACHINE 2 ShoetI-lhoet 1 Filed April 15, 1970 Ev j a 9/50 by W04 United States Patent 3,618,341 WARP KNITTING MACHINE Engelbert Ehrlich, Floha, Saxony, and Bertram Frenzel, Wolfgang Neubert, Friedrich Schattauer, and Wolfgang Wunsch, Karl-Marx-Stadt, Germany, assignors to VEB Wirkmaschinenbau Karl-Marx-Stadt, Karl-Marx-Stadt,

I Germany Filed Apr. 13, 1970, Ser. No. 27,889 Int. Cl. D04b 23/12 UaS- C]. 66-84 7 Claims ABSTRACT OF THE DISCLOSURE In a warp knitting machine in which a preformed weft is fed to a knitting zone in which warp yarns are knit t-hereinto, the improvement comprising means for feeding at least two preformed wefts side by side through the knitting zone and thereby forming a corresponding two longitudinal strips of fabric.

This invention relates to warp knitting machines, particularly of the Mali type, in which preformed wefts are fed to a knitting zone in which a system of knitting needles encloses the wefts in warp knitting or in fringe crochet stitches.

In the known machines of this type the wefts are carried by a pair of transversely spaced feeding means. Generally, the wefts are threaded up on the feeding means as a band of yarn extending back and forth transversely between the two feeding means.

The distance between the feeding means corresponds to the working width of such machine. For the simultaneous production of more than one longitudinal fabric on such machines, it was'necessary heretofore to form a single longitudinal strip of fabric the width of which extended across the entire working width of the machine and'to cut the fabric longitudinally. The cutting is effected either on the machine or outside the machine. With this procedure it is possible, if the requirements regarding the properties of the finished product are not too high, to utilize machines having a relatively large working width to produce longitudinal strips of fabric of half or less that width if the market calls for such fabric. The fabrics to be cut into longitudinal strips can be designed so that no rows of wales but only wefts are present in the path along which the cutting is to take place. Moreover, the laying of wefts over the entire Working -width is uneconomical when it is desired ultimately to produce a narrower fabric because a long traversing of the weft laying means slows down the machine. The longitudinal cutting of the fabric results in each longitudinal strip thereby formed having at least one irregular edge which consists of the severed wefts and adjoining rows of wales of the warps. If wales are also provided in the cutting path, cut warps will also be found on the edges after the cutting. Since the wefts terminate freely at the cutting points, that is, they are neither deflected by nor interlaced with the warps, such a cut edge is not sufficiently strong. In the further treatmerit of such a fabric, for example, on tensioning or drying machines, considerable difliculties are encountered. The cut edge is too elastic to be able to withstand the stresses therein occurring. This frequently makes the cutting technique impractical, thus resulting in the uneconomical use of the machines over only a portion of their working width to produce the fabrics which the market demands at a particular time.

It is a principal object of the invention, therefore; to provide a warp knitting machine, particularly of the aforementioned Mali type, which is suitable for the simultaneous productionof a plurality of longitudinal strips of fabric of less than the full working width of the machine and which strips do not have cut edges.

According to the invention, there is provided a warp knitting machine in which there are means for feeding at least two preformed wefts to the knitting zone and corresponding means for laying the weft yarns onto the respective feeding means.

In the machine of the invention a plurality of longitudinal fabric strips whose edges resist any normal stresses during further processing can be produced simultaneously. Furthermore, due to the shortened path of the respective weft laying means, the output of the machine is increased.

The invention will be further described by reference to the drawings, in which:

FIG. 1 is a schematic drawing of a Mali machine according to the invention in which two yarns are laid in the form of two wefts side by side on respective weft feeding means; and

FIGS. 2 and 3 schematically illustrate arrangements alternative to that of FIG. 1 for guiding the two weft laying means.

For the production of two firmly edged longitudinal strips of fabric, a warp knitting machine, such as of the Mali type, is provided with two weft laying means 31 and 32, respectively, which lay respective continuous yarn bands, for example in a zig-zag pattern in a plane 33 extending perpendicularly to the plane of the drawing (FIG. 1). To this end, the yarns 34, 35 are withdrawn from respective bobbins 36, 37. Thus are formed respective longitudinal strips 38, 39 of wefts, the wefts being formed by the yarns 34 and 35 stretched respectively between feeding means 40 and 41 and feeding means 41 and 42. The feeding means feed the preformed wefts to a row of knitting needles 43 defining a knitting zone in which the yarns 34, 35 of the longitudinal strips 38, 39 of preformed wefts are interlooped with warp yarns. The longitudinal strips 38, 39 of preformed wefts are suspended separately on the feeding means 41. which is provided with one or two rows of hooks, which are customary in Mali type machines, to engage the yarns 34, 35.

The reciprocal movement of the weft laying means 31, 32 is effected by transmission chains 44, 45; to this end, mounted on the transmission chains 44, 45 are respective pins and 51, pin 50 engaging a slot 52 in weft laying means 31 and pin 51 engaging a slot 53 in weft laying means 32. Pin 50 is positioned on the transmission chain between sprockets 46 and 47 and pin 51 is located between sprockets 48 and 49. When pin 50 is traversing on the transmission chain 44 between sprocket 46 and a sprocket 58 located therebelow, as indicated at 54, it

, moves vertically in slot 52 of weft laying means 31 and,

hence, at this time weft laying means 31 is stationary. Similarly, when pin 51 is traversing on transmission chain 45 between sprocket 49. and a sprocket 61 therebelow, as indicated at 57, it moves vertically in the slot 53 of weft laying means 32 and, hence, at this time weft laying means 32 is stationary. The same applies with respect to the pin 50 and the weft laying means 31, when the pin 50 is traversing between sprocket 47 and a sprocket 59 therebelow, as indicated at 56. Sprockets 62, 63 and g 64, 65 are provided to guide the transmission chains 44 and 45, respectively, outside the working range. Sprockets 62 and 64 drive the transmission chains 44 and 45, respectively, and are driven by a cross slide crank .gear which consists essentially of a crank wheel 66 in the form of a gear wheel, a cross slide 67, a lifting rod 68 and a pinion 69. The crank wheel 66 has a slot 66a which receives the rotary cross slide 67. The pinion 69 is coupled with that of a motor (not shown). There is provided a parallel guide consisting of endless chains 70 and 71 and sprockets 72, 73 for the former and 74, 75

for the latter. The parallel guide functions to keep the lifting rod 68 always in a horizontal position and to transmit the lifting movement of the latter to an endless chain 76. To this end the sprockets 72 and 75 are each a double sprocket and the chains 70, 71 are coupled at the connecting points 77, 78 with the lifting rod 68. The movement of the pinion 69 sets the crank wheel 66 in rotation so that the lifting rod 68 performs a harmonic ascending and descending movement. The ascending and The ascending and descending movement is transformed by means of the chains 76 into a reciprocating movement. The sprockets 79, 80 engaging the chain 76 are thus set in alternate rotations. For the transmission of these movements to the transmission chain 44, the sprocket 79 is a double sprocket with the second sprocket wheel 79a of which meshing with an intermediate gear 81. Mounted on sprocket 62 is a gear 82 which engages with the intermediate gear 81. In the case of the transmission chain 45, a pair of gears 83, 84 serves for its operation. The gear 84 is rigidly connected to the sprocket 64 and the gear 83 is rigidly connected to the sprocket 80.

Assuming the pinion 69 to be rotating clockwise as viewed in FIG. 1, the weft laying means 31 and 32 are each approaching the feeding means 41, in their position indicated in FIG. 1.

After the respective sets of preformed wefts 38 and 39 have passed the knitting needles 43 and thereby interlaced with warp yarns, they reach a roll 85 at which they are lifted from the feeding means 40, 41, 42 and then wound. There are formed two durable edge longitudinal strips 86 and 87 of Mali type fabric.

The embodiment illustrated in FIG. 1 provides for each of the weft laying means 31, 32 a transmission chain 44, 45 and a common drive for both chains by means of the crank gear provided with a cross slide. However, it is also possible to couple both weft laying means 31, 32 with a single transmission chain (FIGS. 2 and 3). Likewise, a separate crank gear provided with a cross slide can be provided for each transmission chain 44, 45.

The production of different widths of the longitudinal strips of fabric 86, 87 is possible in the machine according to FIG. 1 by moving the feeding means 41 and the sprockets 47, 59, 48, 60 either to the right or left and adapting correspondingly the path of the weft laying means 31, 32 by varying the transmission ratio of the gear wheels 79a, 82 and 83, 84 respectively. If it is necessary to produce varying widths of fabric on a machine which has only one transmission chain to which the two weft laying means 31, 32 are connected, the arrangements shown in FIGS. 2 and 3 are preferred.

As shown in FIG. 2, a transmission chain 88, of which only the part in the range of the weft laying movement is represented, is deflected several times about corresponding several sprockets 89. There is achieved with equal length paths of the pins 50, 51 different widths of traverse of the weft laying means 31, 32. The weft laying means 31 and 32 are supported by sets of rollers 90 and 91, respectively, which rest on guides 92 and 93. For carrying the transmission chain 88 on the right hand side, sprockets 94 and 95 are provided, which correspond generally to the sprockets 49, 61 or 47, 59 of the arrangement of FIG. 1.

If repeated deflection of the transmission chain 88 is to be avoided, it is possible to design a weft laying means 31 or 32 so that it is temporarily detachable from the transmission chain 88 at its reversing point; such arrangement is illustrated in FIG. 3. Thus, there is provided in the weft laying means 31 a slot 96 having an open end through which the pin 50 leaves the slot when the pin 50 reaches the circumference of a sprocket 97 which is an end position comparable to an end position 99 when the pin 50 reaches a point on the transmission chain between sprockets 103 and 104. When the pin 50 is moving outside of the slot 96, the weft laying means 31 remains at rest. The weft laying means 32, however, moves towards the end position 99. During the opposite direction of movement of the chain 88, a connection of the chain 88 and the weft laying means 31 takes place again at the periphery of the sprocket 97 so that the movement of the weft laying means 31 to the right is started. When the pin 50 is at its far left hand extremity 98, pin 51 and with it weft laying means 32 is at its far left hand extremity 99. correspondingly, when pin 50 and with it weft laying means 31 is at its far right hand extremity 99, pin 51 and with it weft laying means 32 is at its far right hand extremity defined by the pin 51 being between sprockets 105 and 106. Sprocket 102 together with sprocket 97 serves to guide the pin 50 upwards to a level at which it may leave the slot 96. Sprocket 101 guides the chain horizontally so that the pin 50 may leave or enter, respectively, the slot 96. A sprocket defines the left hand extremity of the path of the chain.

The few embodiments herein described are merely by way of illustration and can, of course, be varied or combined with each other. If more than two weft laying means are employed, the principle of the invention is equally applicable in a simliar manner. It is irrelevant with respect to the invention whether the sets of wefts 38, 39 consist of zig-zag or parallel yarns 34, 35 or how these sets of wefts are formed.

What is claimed is:

1. In a warp knitting machine comprising means for laying yarn in the form of a continuous weft on a. weft feeding means, means for feeding the wefts to a knitting zone defined by a set of knitting needles in which the wefts are interlaced by warp threads by means of the knitting needles, the improvement comprising means for forming at least two yarns into a corresponding number of continuous wefts side by side and means for feeding the side by side wefts to the knitting zone thereby simultaneously to form side by side two longitudinal strips of. fabric.

2. A warp knitting machine according to claim 1, comprising two weft laying means and two weft feeding means.

3. A warp knitting machine according to claim 2, in which the two weft feeding means comprises three essentially parallel longitudinal sets of means for engaging the yarns, one end set and the middle set being positioned to carry one of the continuous wefts and the other end set and the middle set being positioned to carry the other continuous weft, each respective weft laying means being.

positioned always to cooperate with a respective one,of the thus defined sets of yarn engaging-means.

4. A warp knitting machine according to claim 3, in which each weft laying means is driven by a separate transmission chain.

5. A warp knitting machine according to claim 3, in which a single transmission chain drives both weft laying means.

6. A warp knitting machine according to claim 1, in which the weft laying means are carried by a single chain, associated with each weft laying means is a weft feeding means, the width of at least one of said weft feeding means differing from the width of at least one other of said weft feeding means, the portion of the chain which carries the weft laying means associated with the weft feeding means of lesser width being so deflected from a straightpath that the weft laying means carried thereby traverses the width of the weft feeding means oflesser width while the weft laying means associated with the weft feeding means of greater width traverses that latter width.

7. A warp knitting machine according to claim 1, in which the weft laying means are carried by a single chain, associated with each weft laying means is a weft feeding means, the width of at least one of said weft feeding means differing from the width of at least one other of said weft feeding means, the weft laying means associated with the weft feeding means of lesser width being adapted to disengage from the chain during a portion of the travel of the chain whereby that weft laying means traverses only 5 the width of the weft feeding means associated therewith 3,446,038 5/1969 Invi 66-84 while the other weft laying means traverses the greater 2,890,579 /1959 Mauersberger 66-86 UX width of the other weft feeding means.

RONALD FELDBAUM, Primary Examiner References Cited 5 UNITED STATES PATENTS 28-1; 66-86 3,440,840 4/1969 Frenzel 66-84 3,523,432 8/1970 Vajda et a1. 66-85 X 

